If you do a search (hint) you'll see I had suggested these two options:
1. Radio Shack selectable 3-12 V 800 mA regulated and filtered adapter (F plug, tip negative) (big!!)
2. Radio Shack 9 V 1200 mA regulated International adapter (F plug, tip negative) (tiny!!)
There is a non-regulated, non-filtered 9 V adapter as well (cheapest choice).
The regulated adapters supply 9 volts, +/- .1, which is pretty damned good, and they have more than enough amperage for the D-25S. The unregulated adapter has a wider range -- the ones I tested had 12-13 volts without a load.
The filtered adapter will remove any powerline noise -- and proved to cure a hum problem I had with some desktop computer speakers/amp.
(I bought both. The big one sits on the desk, and can run three other units I have -- so in the long run it's a best buy -- and the small one can travel.)